Bayern Munich host Real Madrid in Wednesday's mouthwatering Champions League quarterfinal, first-leg, with Carlo Ancelotti's Bavarians looking once again to be the Spaniards' 'bete noire'.

And the subplots to the Allianz Arena clash are fascinating.

Bayern boss Carlo Ancelotti coached Real to the 2014 Champions League crown and is up against his former assistant from that triumph, Madrid's current head coach Zinedine Zidane.

World Cup 2010 winner Xabi Alonso, who also won the 2014 Champions League before joining Bayern, will face his ex-club for the last time before retiring in June.

And Real's Germany midfielder Toni Kroos is another to be coming up against his former employers.

Ancelotti says "little things will make the difference" between the star-studded squads that will see two goal-scoring giants go head-to-head.

Bayern's top-scorer Robert Lewandowski, with 38 goals in all competitions this season, is up against Portuguese superstar Cristiano Ronaldo, with 26 goals from 36 games.

That may be modest by his standards, but Ronaldo has tormented Bayern in the past with four goals in as many games and the Bavarians will be wary, especially with backup from Wales star Gareth Bale and France's Karim Benzema.

Lewandowski suffered a bruised shoulder in scoring twice in Saturday's 4-1 hammering of Borussia Dortmund, but expects to be "100 percent" fit.

Bayern are on a Champions League record of 16 straight European wins at the Allianz Arena and that's a record Dutch winger Arjen Robben is keen to maintain.

"We have to up the ante, we have to signal (to Real) from the first minute that there is nothing to take in Munich and we want to win the game," he said.

Bayern are looking to recover their 'bete noire' nickname, given to them by Real fans after Munich won eight of 14 matches against Real between 2000 and 2012.

All that changed in the 2014 Champions League's semi-final when the team coached by Pep Guardiola was thrashed 4-0 in Munich, crashing out 5-0 on aggregate as Ronaldo and Sergio Ramos netted twice each.

That defeat remains Bayern's record home European loss, yet there is no talk of revenge ahead of Wednesday's clash.

"This is the quarterfinals, but it sounds like a final," said Bayern captain Philipp Lahm.

"We're playing against an absolute top team, who have top players in every position. We will have to play to our potential."

Both sides are missing key defenders, though.

Germany's Mats Hummels was ruled out after damaging ankle ligaments on Sunday so Jerome Boateng and Javi Martinez will form the centre-back partnership.

Hummels faces a race against time to be back for the return at the Santiago Bernabeu on April 18, while Real have defenders Pepe and Raphael Varane ruled out of both legs.